C. elegans is a remarkably good system for studying issues of development and in many ways bridge the experimental and informational gap between single cell and complex animal models. To enable better understanding of gene function throughout development and within cell lineage's we aim to develop a system for lox/Cre recombination mediated control of gene expression. We will first test the ability of Cre recombinase to turn on a GFP reporter construct. lox sites will flank the GFP gene such that lox/Cre recombination will invert the gene and allow for its transcription. We also aim to develop targeted chromosomal integration via high efficiency site- specific recombination, which may eventually enable development of the first cDNA screening scale transformation technology in metazoans. We will test the ability of Cre recombination to direct transgene integration into a chromosomally placed lox site. This proposal holds two main points of innovation. First, efficient site specific recombination may bypass the requirement of introducing large quantities of DNA (for extrachromosomal array formation) and open up the potential of transformation by population scale technologies such as electroporation or coated particle bombardment. Second, the use of site specific recombination to directly integrate a transgene may bypass the mechanisms that shut down transgenes expression. PROPOSED COMMERCIAL APPLICATIONS: Eon intends to commercialize this lox/Cre work through: 1) sub-licensing arrangements within industry, 2) in-house contract research using expertise and materials developed with the lox/Cre system, and 3) in-house use of the lox/Cre transformation system for the identification of drug targets and the targets of drug tonicities. Sale of the system (lox containing worms and ox containing transformation vector) and supplies (injection quality Cre recombinase) in the form of a kit to academic researchers may be considered if no commercial source of injection quality Cre is found.